Heart Rate Zones
Estimated maximum heart rate (Fox or Tanaka), heart rate reserve and five training zones — as a straight percentage of max or with the Karvonen method.
Karvonen uses resting HR for more personalised zones — enter it above.
Enter age to calculate heart-rate zones.
Formulas
HRmax (Fox) = 220 − age
HRmax (Tanaka) = 208 − 0.7 × age
HRR = HRmax − HRrest
Karvonen target = HRR × intensity + HRrest
%HRmax target = HRmax × intensity
Zones: 50–60 · 60–70 · 70–80 · 80–90 · 90–100 %
How It Works
Fox is the easiest to teach but underestimates maximum heart rate in people over about 40; Tanaka holds up better across ages. Karvonen accounts for fitness through resting heart rate, so two clients of the same age get different zones — switch methods live to show the difference.
Sources
- Fox SM, Naughton JP, Haskell WL (1971). Ann Clin Res 3(6):404–432.
- Tanaka H, Monahan KD, Seals DR (2001). J Am Coll Cardiol 37(1):153–156.
- Karvonen MJ, Kentala E, Mustala O (1957). Ann Med Exp Biol Fenn 35(3):307–315.
Questions
What is the difference between %HRmax and Karvonen zones?
Percentage of max multiplies the estimated maximum heart rate. Karvonen applies the percentage to heart rate reserve (max minus resting) and adds resting heart rate back, which personalises zones to fitness.
Is 220 minus age accurate?
It is a rough estimate that tends to underestimate maximum heart rate after about age 40. The Tanaka formula (208 − 0.7 × age) is more accurate across ages.
From Classroom to Clients
When your students start coaching, TrainerQ runs these same calculations on real clients — with programs, progress reports and bookings in one place. Free for coaches.